The milk from a milking animal, such as a cow, is of a certain quality. The milk quality can be defined in different ways, such as for example in terms of its fat content or as having a certain cell count value. Further, the quality level may depend on various factors, for example the feed she is given, her health, her age, stage of lactation, or intervals between milking occasions, to mention a few factors. Besides such environmental factors, the milk quality also depends on genetic factors; the potential fat content of milk from an individual cow is to some extent determined genetically, as are protein and lactose levels.
Depending on its quality, the milk is suitable for different purposes, for example suitable for producing different types of milk-related products. The milk can e.g. be adequate either for direct consumption, for the processing into high-quality products such as cheese, butter or yogurt, for feeding calves or it may be totally unfit for any use.
There are a number of regulations to follow, in which the quality level required for a certain use is stated. For example, it may be regulated that the somatic cell count has to be below a value of 400,000 cells/ml in order for the milk to be consumed by people.
Today, when a farmer delivers an amount of milk to a dairy producer he can obtain an indication of the milk quality as measured by the dairy producer. Alternatively, he may manually measure the quality of the milk in the milk tank at any desired point of time.